Which of the following options is NOT a type of conductor run that must always be followed?

The correct answer highlights that "All of these" is not a specific type of conductor run that must be universally followed in every situation. This option indicates that the other types listed—Class I main conductor, service entrance conductor, and buried conductor—are types of conductors that have specific installation procedures and requirements. These procedures are essential for ensuring safety, compliance with codes, and the effectiveness of the lightning protection system.

Class I main conductors are typically required for systems that provide a primary means of lightning strike dissipation. Service entrance conductors are vital for connecting the electrical service to the building and ensuring proper grounding. Buried conductors are necessary for underground installations and have their own set of guidelines due to environmental and installation factors.

By choosing "All of these," it implies that each type has its own requirements and that not every situation mandates the same type of conductor run. Therefore, saying "All of these" as an option that does not list a type of conductor run emphasizes the variability and specificity needed in lightning protection system installations.